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The company says the contact dermatitis is likely caused by nickle, adhesives or other materials

Complaints of itchy, irritated wrists have prompted Fitbit to voluntarily recall all of its Fitbit Force wristband activity trackers.

About 1.7% of Force users reported cases of skin rashes after wearing the devices, Fitbit CEO James Park said in a letter to customers on Friday afternoon. The cause of the irritation, which is assumed to be allergic contact dermatitis, is either the nickel that's in the stainless steel part of the device, or adhesives or other materials used in the strap.

The $130 Force wearable pedometer was released at the end of 2013 and is the most recent product from the fitness hardware company. The Force is a silicon wristband with a small display and sensors for measuring motion. It tracks the wearer's number of steps, calories burned, distance traveled, and sleep patterns and syncs the information to a computer or smartphone.

"On behalf of the entire Fitbit team, I want to apologize to anyone affected," Park said. "From the beginning, we have taken this matter very seriously."

The company first acknowledged the complaints last month and said that anyone who experienced skin irritation could return their device for a full refund or a replacement tracker. Since then, the company has conducted a more complete investigation of the devices and ruled out any problems with the electrical or hardware elements.

Any Force owners interested in returning their wristbands for a full refund can fill out a form on the Fitbit website or call the company's customer service center. They'll receive a kit to mail the Force back to the company and should receive a refund check in two to six weeks.

This is not the first time a wearable fitness device has run into quality issues. In 2012, Jawbone offered full refunds to customers who purchased its buggy UP wristband activity tracker.

Fitbit still sells its other popular trackers, including the older Flex wristband and wearable trackers that clip onto clothes. The company also has plans for future replacement products.

"Rest assured we're working on our next-generation tracker and will announce news about it soon," Park said.